I have a question regarding distances and how they were measured during the civil war. I would like to know exactly how the troops were able to measure a mile, for example. One highly educated soldier stated that "he was located 2 1/2 miles from a known town". Can we assume it was exactly 2 1/2 miles, or was it a guesstimate? I'm sure the distances mentioned were actual road miles and not "as the crow flies". Anyone that can elaborate on how they were able to measure a given distance accurately, please let me know. Thank you.